Faculty Bibliography

Findings from previous research have argued for the dissociation of two visual-perceptual tasks traditionally thought to be mediated by the nondominant hemisphere (i.e. perceptual closure and facial discrimination). This, primarily methodological, study examined the extent to which the facial closure measure (Mooney closure faces test) involves 'closure' and/or facial discrimination. A factor analysis of six visual perceptual measures, carried out separately for left brain damaged (LBDs, n=33) and right brain damaged (RBDs, n=30) patients, resulted in two relatively independent factors (i.e. a closure factor and a facial discrimination factor), with the Mooney closure faces test loading on both. The mixed factorial structure did not aid the facial closure measure's sensitivity to right-sided brain disease. Moreover, age and education intercorrelated differently with the two factors. Results argue for the use of more discrete visual-perceptual measures when examining perceptual functioning and/or right hemisphere integrity, and imply the existence of at least two discrete cortical level visual-perceptual neural systems

CONTEXT: Approximately 300 000 sport-related concussions occur annually in the United States, and the likelihood of serious sequelae may increase with repeated head injury. OBJECTIVE: To estimate the incidence of concussion and time to recovery after concussion in collegiate football players. DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study of 2905 football players from 25 US colleges were tested at preseason baseline in 1999, 2000, and 2001 on a variety of measures and followed up prospectively to ascertain concussion occurrence. Players injured with a concussion were monitored until their concussion symptoms resolved and were followed up for repeat concussions until completion of their collegiate football career or until the end of the 2001 football season. MAIN OUTCOME MEASURES: Incidence of concussion and repeat concussion; type and duration of symptoms and course of recovery among players who were injured with a concussion during the seasons. RESULTS: During follow-up of 4251 player-seasons, 184 players (6.3%) had a concussion, and 12 (6.5%) of these players had a repeat concussion within the same season. There was an association between reported number of previous concussions and likelihood of incident concussion. Players reporting a history of 3 or more previous concussions were 3.0 (95% confidence interval, 1.6-5.6) times more likely to have an incident concussion than players with no concussion history. Headache was the most commonly reported symptom at the time of injury (85.2%), and mean overall symptom duration was 82 hours. Slowed recovery was associated with a history of multiple previous concussions (30.0% of those with > or =3 previous concussions had symptoms lasting >1 week compared with 14.6% of those with 1 previous concussion). Of the 12 incident within-season repeat concussions, 11 (91.7%) occurred within 10 days of the first injury, and 9 (75.0%) occurred within 7 days of the first injury. CONCLUSIONS: Our study suggests that players with a history of previous concussions are more likely to have future concussive injuries than those with no history; 1 in 15 players with a concussion may have additional concussions in the same playing season; and previous concussions may be associated with slower recovery of neurological function.

CONTEXT: Lack of empirical data on recovery time following sport-related concussion hampers clinical decision making about return to play after injury. OBJECTIVE: To prospectively measure immediate effects and natural recovery course relating to symptoms, cognitive functioning, and postural stability following sport-related concussion. DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study of 1631 football players from 15 US colleges. All players underwent preseason baseline testing on concussion assessment measures in 1999, 2000, and 2001. Ninety-four players with concussion (based on American Academy of Neurology criteria) and 56 noninjured controls underwent assessment of symptoms, cognitive functioning, and postural stability immediately, 3 hours, and 1, 2, 3, 5, 7, and 90 days after injury. MAIN OUTCOME MEASURES: Scores on the Graded Symptom Checklist (GSC), Standardized Assessment of Concussion (SAC), Balance Error Scoring System (BESS), and a neuropsychological test battery. RESULTS: No player with concussion was excluded from participation; 79 players with concussion (84%) completed the protocol through day 90. Players with concussion exhibited more severe symptoms (mean GSC score 20.93 [95% confidence interval [CI], 15.65-26.21] points higher than that of controls), cognitive impairment (mean SAC score 2.94 [95% CI, 1.50-4.38] points lower than that of controls), and balance problems (mean BESS score 5.81 [95% CI, -0.67 to 12.30] points higher than that of controls) immediately after concussion. On average, symptoms gradually resolved by day 7 (GSC mean difference, 0.33; 95% CI, -1.41 to 2.06), cognitive functioning improved to baseline levels within 5 to 7 days (day 7 SAC mean difference, -0.03; 95% CI, -1.33 to 1.26), and balance deficits dissipated within 3 to 5 days after injury (day 5 BESS mean difference, -0.31; 95% CI, -3.02 to 2.40). Mild impairments in cognitive processing and verbal memory evident on neuropsychological testing 2 days after concussion resolved by day 7. There were no significant differences in symptoms or functional impairments in the concussion and control groups 90 days after concussion. CONCLUSIONS: Collegiate football players may require several days for recovery of symptoms, cognitive dysfunction, and postural instability after concussion. Further research is required to determine factors that predict variability in recovery time after concussion. Standardized measurement of postconcussive symptoms, cognitive functioning, and postural stability may enhance clinical management of athletes recovering from concussion

Animal word list generation (ANWLG) was administered to 47 first-episode schizophrenia (FES) participants and 31 controls. Fifty-nine left temporal lobe epilepsy (LTLE) participants were included as a comparison group with known temporal lobe damage and expected semantic deficits. Semantic knowledge was assessed with the Association Index (AI), a measure of the semantic relatedness of all consecutive ANWLG responses. Neuropsychological tests of language and executive functioning were also administered. Results showed that both FES and LTLE groups generated fewer ANWLG responses than controls, but only the LTLE participants obtained a lower AI relative to controls. FES participants did not differ from controls on the AI. FES and LTLE groups produced fewer semantic subcategories (clusters), however, only the LTLE group produced fewer words per subcategory compared to controls (cluster size). FES participants produced a higher rate of perseverative responses compared to the other groups. Finally, correlation analyses showed that for FES participants both executive and language tests significantly correlated with ANWLG total responses, while the correlation between ANWLG and only 1 language test was significant for LTLE participants. Taken together, the results suggest that reduced ANWLG output in FES participants may be best conceptualized as a deficit in the executive component of word list generation (i.e., semantic search/access, response monitoring) or global cognitive impairment.

This study provides preliminary norms and test-retest indices on a brief battery of neuropsychological tests administered to a sample of 60 male and 40 female high school athletes. Forty-eight subjects completed retesting 8 weeks later. Analyses of baseline scores indicate that girls outperform boys on selected measures of processing speed and executive functions [Wechsler Adult Intelligence Scale-III (WAIS-III) Digit Symbol, Trails B, and Controlled Oral Word Association Test (COWAT)]. Test-retest reliability was low and varied widely among the tests. There were no gender differences in test-retest reliability. Reliable Change Indices (RCIs) were computed on the test-retest data for use in clinical interpretation. These preliminary results indicate that caution should be used in interpreting neuropsychological test data from high school athletes. The current findings indicate that separate norms for boys and girls are warranted. Caution should be used in interpreting discrepancies from baseline scores as a result of what may turn out to be poor test-retest reliability in this population

OBJECTIVE: To prospectively examine recovery of cognitive function within one month following subconcussive sports related head trauma. DESIGN: A prospective study of New York State licensed professional boxers who underwent testing of cognitive functioning before and after (within days, one week, and one month) a professional bout. SETTING: Male professional athletes recruited from the New York State Athletic Commission and local boxing gyms. PARTICIPANTS: Twenty-six licensed professional boxers were enrolled in the protocol. Data is presented on the 18 participants who completed testing on at least three of the four time points. INTERVENTIONS: Serial neuropsychological assessment before and after the athletes engaged in competition. MAIN OUTCOME MEASURES: Neuropsychological measures of cognitive functioning, including new learning and memory, information processing speed, and mental flexibility. RESULTS: A series of repeated measures MANOVAS revealed significant within subject differences across testing on complex information processing and verbal fluency. Post hoc analyses indicated significant differences between time 1 (baseline) and time 4 (one month post), with scores one month following the bout indicating significantly improved performance. Memory scores did not change significantly across testing; however, prior boxing exposure measured by total number of professional bouts was associated with poorer memory performance. CONCLUSIONS: Cognitive testing one month following participation in a professional boxing bout yielded scores suggestive of recovery to a level above the baseline. We conclude that baseline assessment taken during periods of intense training are likely confounded by other pre-bout conditions (i.e., sparring, rapid weight loss, pre-bout anxiety) and do not represent true baseline abilities. Instability of performance associated with mild head injury may complicate the interpretation of post-injury assessments. Practice effects may also confound the interpretation of serial assessments, leading to underestimation of the effects of sports related head trauma. Poorer cognitive performance was evident during the presumed recovery period in boxers with greater exposure to the sport (>12 professional bouts). This finding is consistent with reports of a cumulative effect of repetitive head trauma and the subsequent development of chronic traumatic brain injury. These data have implications for assessing recovery of function following head injury in players of other contact sports as well as determination of return-to-play following an injury.